DTC 43: Last Message Received With SUMCHECK Error: Description

The digital RF message received was from a Remote Keyless Entry (RKE) transmitter that is programmed to Body Control Module (BCM), but message did not pass sumcheck security test. No remote function capabilities will exist.

DTC 43 will set when BCM is in diagnostic mode, any RKE transmitter button is pressed and RKE transmitter signal does not pass sumcheck security test. Most likely cause is that RKE transmitter is out of synchronization.